The invention relates to skin cleansing compositions containing major amounts of acyl isethionates and exhibiting improved skin mildness. 2. The Prior Art
Traditionally, soap has been utilized as a skin cleanser. Soap is, however, a very harsh chemical. Irritated and cracked skin result from use of soap, especially in colder climates. Of course, there are certain benefits from soap including that of low cost, easy manufacture into bars, and good lathering qualities.
There has been much commercial activity to replace soaps with milder surfactants. Particularly successful has been the introduction of syndet mild toilet bars, especially those based on sodium cocoyl isethionates. Patents relating to this technology include U.S. Pat No. 2,894,912 (Geitz) disclosing a detergent bar containing 30-70% C.sub.6 -C.sub.18 acyl esters of isethionic acid, a suds-boosting detergent salt such as 2-10% alkyl sulfate and 2.5-25% soap.
U.S. Pat. No. 4,007,125 (Prince) suggests that greater than 75% of the isethionate ester be in the C.sub.12 -C.sub.18 acyl range. the other hand, U.S. Pat. No. 3,879,309 (Gatti et al.) notes that superior lathering may be achieved by use of lower chain length fatty residues. The patent suggests a mixture of isethionate esters with a fatty acyl distribution of about 28-37% C.sub.10, about 18-24% C.sub.12, about 16-21% C.sub.14, about 9-20% C.sub.16, and about 10.17% C.sub.18 chain lengths.
U.S. Pat. No. 4,206,069 (Borrello) obtains transparent toilet bars by combining surfactants among which are the oleic ester of isethionic acid and the C.sub.8 -C.sub.24 alkyl ether sulfates having 1-20 ethylene oxide units.
U.S. Pat. No. 4,335,025 (Barker et al.) reports combinations of 4-20% C.sub.10 -C.sub.16 acyl isethionate with, among others, 18-35% C.sub.8 -C.sub.16 alkyl sulfosuccinate.
The present invention seeks compositions with even better skin mildness than those aforementioned while also improving upon lather, mush and processing properties.
Thus, it is an object of this invention to provide a skin cleansing composition based upon acyl isethionates as the main actives but substantially milder to the skin than such previously known compositions.
These and other objects of the invention will become more readily apparent through the following summary and detailed description.